diff options
Diffstat (limited to 'arch/parisc/include/asm/uaccess.h')
| -rw-r--r-- | arch/parisc/include/asm/uaccess.h | 59 |
1 files changed, 34 insertions, 25 deletions
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h index edfbf9d6a6dd..8442727f28d2 100644 --- a/arch/parisc/include/asm/uaccess.h +++ b/arch/parisc/include/asm/uaccess.h @@ -65,6 +65,15 @@ struct exception_table_entry { ".previous\n" /* + * ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry + * (with lowest bit set) for which the fault handler in fixup_exception() will + * load -EFAULT into %r8 for a read or write fault, and zeroes the target + * register in case of a read fault in get_user(). + */ +#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr )\ + ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1) + +/* * The page fault handler stores, in a per-cpu area, the following information * if a fixup routine is available. */ @@ -91,7 +100,7 @@ struct exception_data { #define __get_user(x, ptr) \ ({ \ register long __gu_err __asm__ ("r8") = 0; \ - register long __gu_val __asm__ ("r9") = 0; \ + register long __gu_val; \ \ load_sr2(); \ switch (sizeof(*(ptr))) { \ @@ -107,22 +116,23 @@ struct exception_data { }) #define __get_user_asm(ldx, ptr) \ - __asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \ - ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\ + __asm__("1: " ldx " 0(%%sr2,%2),%0\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ : "=r"(__gu_val), "=r"(__gu_err) \ - : "r"(ptr), "1"(__gu_err) \ - : "r1"); + : "r"(ptr), "1"(__gu_err)); #if !defined(CONFIG_64BIT) #define __get_user_asm64(ptr) \ - __asm__("\n1:\tldw 0(%%sr2,%2),%0" \ - "\n2:\tldw 4(%%sr2,%2),%R0\n\t" \ - ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\ - ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\ + __asm__(" copy %%r0,%R0\n" \ + "1: ldw 0(%%sr2,%2),%0\n" \ + "2: ldw 4(%%sr2,%2),%R0\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ : "=r"(__gu_val), "=r"(__gu_err) \ - : "r"(ptr), "1"(__gu_err) \ - : "r1"); + : "r"(ptr), "1"(__gu_err)); #endif /* !defined(CONFIG_64BIT) */ @@ -148,32 +158,31 @@ struct exception_data { * The "__put_user/kernel_asm()" macros tell gcc they read from memory * instead of writing. This is because they do not write to any memory * gcc knows about, so there are no aliasing issues. These macros must - * also be aware that "fixup_put_user_skip_[12]" are executed in the - * context of the fault, and any registers used there must be listed - * as clobbers. In this case only "r1" is used by the current routines. - * r8/r9 are already listed as err/val. + * also be aware that fixups are executed in the context of the fault, + * and any registers used there must be listed as clobbers. + * r8 is already listed as err. */ #define __put_user_asm(stx, x, ptr) \ __asm__ __volatile__ ( \ - "\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \ - ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\ + "1: " stx " %2,0(%%sr2,%1)\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ : "=r"(__pu_err) \ - : "r"(ptr), "r"(x), "0"(__pu_err) \ - : "r1") + : "r"(ptr), "r"(x), "0"(__pu_err)) #if !defined(CONFIG_64BIT) #define __put_user_asm64(__val, ptr) do { \ __asm__ __volatile__ ( \ - "\n1:\tstw %2,0(%%sr2,%1)" \ - "\n2:\tstw %R2,4(%%sr2,%1)\n\t" \ - ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\ - ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\ + "1: stw %2,0(%%sr2,%1)\n" \ + "2: stw %R2,4(%%sr2,%1)\n" \ + "9:\n" \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(1b, 9b) \ + ASM_EXCEPTIONTABLE_ENTRY_EFAULT(2b, 9b) \ : "=r"(__pu_err) \ - : "r"(ptr), "r"(__val), "0"(__pu_err) \ - : "r1"); \ + : "r"(ptr), "r"(__val), "0"(__pu_err)); \ } while (0) #endif /* !defined(CONFIG_64BIT) */ |